Semiconductor nanowires are gaining interest as components for micro- and nanoscale devices due to their novel electrical and optical properties that include new realms of physics stemming from the quantum mechanical dimension of these nanowires. Materials such as SiGe, strained Si, superlattices, and quantum wells in their bulk form have unique properties, which make these materials useful in a number of optical and electrical devices.
Traditionally, silicon nanowires have been grown epitaxially on top of a silicon substrate using chemical vapor deposition method, such as the method described in US2007/0222074 A1 or growing Si nanowires in a patterned template defined by diblock copolymer on top of a silicon substrate. US2006/0098705 A1 describes a method of growing Si nanowires and quantum dots on top of a patterned silicon substrate by the chemical vapor deposition (CVD) method. US 2005/0248003 A1 describes a method of forming heterojunction nanowires by a chemical vapor method. US 2007/0235738 A1 describes a method to form p-Si/n-Si nanowire junction with embedded quantum dots by CVD.
The chemical method of etching a uniformly doped Si substrate to form Si nanowires has been discussed in the published work of K. Q. Peng et al. (Adv. Mater. 14(2002) 1164; J. Electroanal. Chem. 558 (2003) 35; Adv. Funct. Mates. 13 (2003) 127.). FIG. 1 shows a schematic of how silicon nanowires were obtained by the method of Peng et al.